{-# LANGUAGE Safe #-}

{-|
Module      : Data.Char.Math.Internal
Description : A module to write math unicode alphanumerical characters.
Maintainer  : hapytexeu+gh@gmail.com
Stability   : experimental
Portability : POSIX

Internal functions for the Math module.
-}

module Data.Char.Math.Internal
  ( _shiftC
  , _ordc
  , _baseUpperLower
  , _baseUpperLowerNum
  , _isValidInt
  , _withCondition
  , _dispatchLatinGreekDigit
  , _dispatchLatinGreekDigit'
  ) where

import Data.Char (chr, isAsciiUpper, isDigit, ord)
import Data.Char.Core (isAsciiAlpha, isGreek)

_shiftC :: Int -> Char -> Char
_shiftC :: Int -> Char -> Char
_shiftC = (Int -> Char
chr forall b c a. (b -> c) -> (a -> b) -> a -> c
.) forall b c a. (b -> c) -> (a -> b) -> a -> c
. (forall b c a. (b -> c) -> (a -> b) -> a -> c
. Char -> Int
ord) forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall a. Num a => a -> a -> a
(+)

_ordc :: Char -> Int -> Char
_ordc :: Char -> Int -> Char
_ordc = (Int -> Char
chr forall b c a. (b -> c) -> (a -> b) -> a -> c
.) forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall a. Num a => a -> a -> a
(+) forall b c a. (b -> c) -> (a -> b) -> a -> c
. Char -> Int
ord

_baseUpperLower :: Int -> Char -> Char
_baseUpperLower :: Int -> Char -> Char
_baseUpperLower Int
b Char
c
    | Char -> Bool
isAsciiUpper Char
c = Int -> Char
oc (Int
bforall a. Num a => a -> a -> a
+Int
6)
    | Bool
otherwise = Int -> Char
oc Int
b
    where oc :: Int -> Char
oc = Char -> Int -> Char
_ordc Char
c

_baseUpperLowerNum :: Int -> Int -> Char -> Char
_baseUpperLowerNum :: Int -> Int -> Char -> Char
_baseUpperLowerNum Int
n Int
b Char
c
    | Char -> Bool
isDigit Char
c = Int -> Char
oc Int
n
    | Char -> Bool
isAsciiUpper Char
c = Int -> Char
oc (Int
bforall a. Num a => a -> a -> a
+Int
6)
    | Bool
otherwise = Int -> Char
oc Int
b
    where oc :: Int -> Char
oc = Char -> Int -> Char
_ordc Char
c

_isValidInt :: Int -> Bool
_isValidInt :: Int -> Bool
_isValidInt Int
x = Int
x forall a. Ord a => a -> a -> Bool
< Int
10 Bool -> Bool -> Bool
&& Int
x forall a. Ord a => a -> a -> Bool
>= Int
0

_withCondition :: (a -> Bool) -> (a -> b) -> a -> Maybe b
_withCondition :: forall a b. (a -> Bool) -> (a -> b) -> a -> Maybe b
_withCondition a -> Bool
p a -> b
f = a -> Maybe b
go
    where go :: a -> Maybe b
go a
x | a -> Bool
p a
x = forall a. a -> Maybe a
Just (a -> b
f a
x)
               | Bool
otherwise = forall a. Maybe a
Nothing

-- | Unsafe dispatch to a conversion function according to the character
_dispatchLatinGreekDigit'
    :: (Char -> Char) -- ^ Latin
    -> (Char -> Char) -- ^ Greek
    -> (Char -> Char) -- ^ Digit
    -> Char        -- ^ Character to transform
    -> Char
_dispatchLatinGreekDigit' :: (Char -> Char) -> (Char -> Char) -> (Char -> Char) -> Char -> Char
_dispatchLatinGreekDigit' Char -> Char
l Char -> Char
g Char -> Char
d Char
c
  | Char -> Bool
isDigit Char
c      = Char -> Char
d Char
c
  | Char -> Bool
isAsciiAlpha Char
c = Char -> Char
l Char
c
  | Char -> Bool
isGreek Char
c      = Char -> Char
g Char
c
  | Bool
otherwise      = Char
c -- Keep the character unchanged

-- | Safe dispatch to a conversion function according to the character
_dispatchLatinGreekDigit
    :: (Char -> Char) -- ^ Latin
    -> (Char -> Char) -- ^ Greek
    -> (Char -> Char) -- ^ Digit
    -> Char        -- ^ Character to transform
    -> Maybe Char
_dispatchLatinGreekDigit :: (Char -> Char)
-> (Char -> Char) -> (Char -> Char) -> Char -> Maybe Char
_dispatchLatinGreekDigit Char -> Char
l Char -> Char
g Char -> Char
d Char
c
  | Char -> Bool
isDigit Char
c      = forall a. a -> Maybe a
Just (Char -> Char
d Char
c)
  | Char -> Bool
isAsciiAlpha Char
c = forall a. a -> Maybe a
Just (Char -> Char
l Char
c)
  | Char -> Bool
isGreek Char
c      = forall a. a -> Maybe a
Just (Char -> Char
g Char
c)
  | Bool
otherwise      = forall a. Maybe a
Nothing